U.S. patent application number 10/405379 was filed with the patent office on 2003-09-04 for drive system for an infinitely variable drive transmission.
Invention is credited to Anderson, Lawrence A..
Application Number | 20030166426 10/405379 |
Document ID | / |
Family ID | 27808007 |
Filed Date | 2003-09-04 |
United States Patent
Application |
20030166426 |
Kind Code |
A1 |
Anderson, Lawrence A. |
September 4, 2003 |
Drive system for an infinitely variable drive transmission
Abstract
An improvement relating to an infinitely variable ratio
transmission having a pair of oppositely oriented variable diameter
torque input and output pulleys is disclosed wherein the conical
surfaces of the pulleys include a multiplicity of axially and
circumferentially movable sprocket bars to accommodate the fixed
length of an inextensible drive belt or chain wrapping about the
pulleys.
Inventors: |
Anderson, Lawrence A.;
(Cincinnati, OH) |
Correspondence
Address: |
c/o Frost Brown Todd LLC
2200 PNC Center
201 East Fifth Street
Cincinnati
OH
45202
US
|
Family ID: |
27808007 |
Appl. No.: |
10/405379 |
Filed: |
April 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10405379 |
Apr 2, 2003 |
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09858434 |
May 16, 2001 |
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6575856 |
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60376661 |
Apr 30, 2002 |
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Current U.S.
Class: |
474/8 ; 474/162;
474/203; 474/69 |
Current CPC
Class: |
F16H 9/08 20130101; F16H
55/38 20130101 |
Class at
Publication: |
474/8 ; 474/69;
474/162; 474/203 |
International
Class: |
F16H 055/56; F16H
059/00; F16G 005/20 |
Claims
I claim:
1. In an infinitely variable ratio transmission having a first
variable diameter pulley torque input member and second variable
diameter pulley output member, wherein said second variable
diameter pulley is oriented with respect to said first variable
diameter pulley such that the axis of rotation of said second
variable diameter pulley is parallel to the axis of rotation of
said first variable diameter pulley wherein torque is transmitted
from said first variable diameter pulley to said second variable
diameter pulley by an endless, inextensible belt, the improvement
comprising: a) a multiplicity of radially extending channels
circumferentially spaced over the conical surfaces of said variable
diameter pulleys, b) a sprocket bar positioned in each of said
radially extending channels for engaging said inextensible belt,
wherein said sprocket bars are free to move both normal to said
pulley's surface and circumferentially within each of said
channels, c) resilient means positioned between said sprocket bars
and their associated channel bottom whereby said sprocket bars are
biased outward toward said pulley's conical surface.
2. The improvement as claimed in claim 1 wherein said inextensible
endless belt comprises a beaded chain.
3. The improvement as claimed in claim 1 wherein said inextensible
belt comprises a linked chain.
4. The improvement as claimed in claim 1 wherein said pulley's
conical surfaces comprise a first conical angle extending from the
smaller diameter end to the midpoint of said conical surface and a
second conical angle extending from said midpoint to the large
diameter end of said pulley's conical surface.
5. The improvement as claimed in claim 4 wherein said first conical
angle is greater than said second conical angle.
6. The improvement as claimed in claim 5 wherein said second
conical angle lies within the range of four to ten percent smaller
than said first conical angle.
7. The improvement as claimed in claim 6 wherein said second
conical angle is six percent smaller than said first conical
angle.
8. The improvement as claimed in claim 1 wherein said pulley's
conical surfaces include three or more conical angles and wherein
said conical angles progressively decrease from the small diameter
end of said pulley's conical surface to the large diameter end of
said pulley's conical surface.
9. The improvement as claimed in claim 1 wherein said sprocket bar
includes a convex bottom surface wherein the high point of said
convexity is positioned at the longitudinal midpoint of said
pulley's conical surface.
10. An infinitely variable ratio drive transmission comprising: a)
a variable diameter pulley input torque member and a variable
diameter pulley output torque member, wherein said variable
diameter pulleys are oriented with respect to one another such that
the axis of rotation of said torque input variable diameter pulley
is parallel to said axis of rotation of said torque output variable
diameter pulley b) an inextensible, endless belt means
circumscribing said variable diameter pulley input torque member
and said variable diameter pulley output torque member whereby said
input torque is transferred from said input variable diameter
pulley to said output variable diameter pulley, c) a multiplicity
of radially extending channels circumferentially spaced over the
conical surface of said variable diameter pulleys, d) a sprocket
bar positioned in each of said radially extending channels for
engaging said belt, wherein said sprocket bars are free to move
both normal to said pulley's conical surface and circumferentially
within said channel, e) resilient means positioned between said
sprocket bars and their associated channel bottom whereby said
sprocket bar is biased outward toward said pulley's conical
surface.
11. The transmission as claimed in claim 10 wherein said inelastic
inextensible endless belt means comprises a beaded chain.
12. The transmission as claimed in claim 11 wherein said beaded
chain includes floating beads.
13. The transmission as claimed in claim 10 wherein said inelastic
inextensible endless belt means comprises a linked chain.
14. The transmission as claimed in claim 10 wherein said variable
diameter pulleys surfaces comprise a first conical angle extending
from the smaller diameter end to the longitudinal midpoint of said
variable diameter pulley's surface and a second conical angle
extending from said longitudinal midpoint to the large diameter end
of said variable diameter pulley.
15. The transmission as claimed in claim 14 wherein said first
conical angle is greater than said second conical angle.
16. The transmission as claimed in claim 15 wherein said second
conical angle lies within the range of four to ten percent smaller
than said first conical angle.
17. The transmission as claimed in claim 16 wherein said second
conical angle is six percent smaller than said first conical
angle.
18. The transmission as claimed in claim 10 wherein said variable
diameter pulleys include three or more conical angles and wherein
said conical angles progressively decrease from the small diameter
end of said variable diameter pulley to the large diameter end of
said variable diameter.
19. An infinitely, variable ratio, drive transmission comprising:
a) a first variable diameter pulley torque input member and a
second matching variable diameter torque output member, wherein the
axis of said first member is parallel to the axis of said second
member b) an endless, inextensible belt means circumscribing said
input torque member and said output torque member whereby said
input torque is transferred from said input torque member to said
output torque member, c) a multiplicity of radially extending
channels circumferentially spaced over the external conical surface
of said input torque and output torque members, d) a sprocket bar
positioned in each of said radially extending channels for engaging
said belt means wherein said sprocket bars are free to move both
normal to said pulley's conical surface and circumferentially
within said channel, e) resilient means positioned between said
sprocket bars and their associated channel bottom whereby said
sprocket bar is biased outward toward said pulley's surface.
20. The transmission as claimed in claim 14 wherein at least one of
said variable diameter pulleys includes a curved surface extending
from said small diameter end to said large diameter end.
21. The transmission as claimed in claim 20 wherein the slope of
the curved surface progressively decreases from said small diameter
end to said large diameter end.
22. An infinitely variable ratio drive transmission comprising: f)
a variable diameter pulley torque input member and a matching
variable diameter pulley torque output member, g) an inextensible
endless belt circumscribing said input torque member and said
torque output member whereby said input torque is transferred from
said torque input member to said torque output member, said belt
including an inextensible runner having a multiplicity of free
floating beads thereon, h) a multiplicity of radially extending
channels circumferentially spaced over said variable diameter
pulley's flanged surface, i) a sprocket bar positioned within each
of said radially extending channels for engaging said belt and
wherein, j) said resilient means is positioned between said
sprocket bars and their associated channel bottom whereby said
sprocket bars are biased outward toward the surface of said
variable pulley's flange surface.
23. The improvement as claimed in claim 1 wherein said variable
diameter pulleys are of differing outside diameters.
24. The improvement as claimed in claim 1 wherein at least one
sheave of at least one of said variable diameter pulleys is at a
right angle to the axis of rotation of said pulley.
25. In an infinitely variable ratio transmission having a first
variable diameter pulley torque input member and second variable
diameter pulley output member, each of said variable diameter
pulleys having a first and second sheave, said second variable
diameter pulley being oriented with respect to said first conical
variable diameter pulley such that the axis of rotation of said
second variable diameter pulley is parallel to the axis of rotation
of said first variable diameter pulley wherein torque is
transmitted from said first variable diameter pulley to said second
variable diameter pulley by an endless, inextensible belt, the
improvement comprising: a) a multiplicity of radially extending
channels circumferentially spaced over the conical surface of said
first sheave of each said variable diameter pulley, b) a sprocket
bar positioned in each of said radially extending channels for
engaging said inextensible belt, wherein said sprocket bars are
free to move both normal to said pulley's surface and
circumferentially within each of said channels, c) resilient means
positioned between said sprocket bars and their associated channel
bottom whereby said sprocket bars are biased outward toward said
pulley's conical surface.
26. The improvement as claimed in claim 25 wherein the extended
surface of said second sheave, of at least one of said variable
diameter pulleys, intersects said axis of rotation at a right
angle.
27. The improvement as claimed in claim 26 wherein the surface of
said second sheave includes: a) a multiplicity of radially
extending channels circumferentially spaced over the conical
surface of said first sheave of each said variable diameter pulley,
b) a sprocket bar positioned in each of said radially extending
channels for engaging said inextensible belt, wherein said sprocket
bars are free to move both normal to said pulley's surface and
circumferentially within each of said channels, c) resilient means
positioned between said sprocket bars and their associated channel
bottom whereby said sprocket bars are biased outward toward said
pulley's conical surface.
Description
RELATED APPLICATIONS
[0001] This application is a continuation in part of my prior
application Ser. No. 09/858,434, filed on May 16, 2001 entitled
"Variable Drive Transmission and is incorporated herein by
reference. Further this application claims the priority of
Provisional Patent Application serial No. 60/376,661 entitled
"Drive System For An Infinitely Variable Drive Transmission" filed
on Apr. 30, 2002.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to a power
transmission whereby the input speed, from a constant velocity,
prime mover, such as an automotive engine, or any other suitable
power source, may be reduced to a desired output speed by the
internal workings of the transmission.
[0003] More specifically the present invention relates to an
infinitely variable ratio drive mechanism, of the endless belt
type, having a pair of radially adjustable V shaped pulleys
configured to rotate on a pair of parallel axes.
[0004] An endless, inextensible, belt or chain encircles and
drivingly engages both pulleys whereby power may be transmitted
from one pulley to the other. A variable speed reduction, between
the pulleys, is obtained by selectively moving at least one sheave
of each pulley toward or away from the other whereby the effective
diameter of the pulleys are controllably varied.
[0005] It is well known to use opposing, variable pulleys as the
driving member and the driven member in power transmissions as
evidenced by the following sampling of U.S. Pat. Nos. 4,433,594;
5,011,461; 6,095,942; 6,135,916; 6,254,503.
[0006] In studying variable pulley transmission drive mechanisms it
becomes apparent that the variable pulley drive mechanism merely
emulates the dual cone variable drive transmission as described in
the parent application. Rather than moving the drive belt, or
chain, radially along the conical members of the dual cone
configuration whereby the operating diameter of the conical members
is varied to obtain a desired input to output RPM reduction, the
axial distance between the sheaves of the variable pulleys is
adjusted thereby emulating the action of the dual cone drive
mechanism taught in the parent application.
SUMMARY OF THE INVENTION
[0007] The present invention teaches novel, free floating sprocket
bars spaced about the surface of variable pulley's conical
surfaces, or sheaves, and extending radially along the conical
surface thereof. The sprocket bars generally parallel the surface
of the pulley's conical surface. However, the sprocket bars may
take any other convenient shape, such as a convex configuration, as
described further below. By being free floating, the sprocket bars
may freely move axially and circumferentially whereby they may
engage a beaded or other suitably configured and generally
inelastic, and inextensible drive chain.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 presents a schematic, end elavational view of the
primary elements of my new and improved transmission.
[0009] FIG. 2 is a sectional view taken along line 2-2 in FIG.
1.
[0010] FIG. 3 is an elevational view taken along line 3-3 in FIG.
2.
[0011] FIG. 4 is a sectional view taken along line 4-4 in FIG.
3.
[0012] FIG. 4A presents an alternate embodiment of the structure
illustrated in FIG. 4.
[0013] FIG. 4B presents a further alternate embodiment of the
structure illustrated in FIG. 4.
[0014] FIG. 5 presents a crossectional view, similar to that of
FIG. 4 showing the floating sprocket bar in engagement with a
beaded drive chain.
[0015] FIG. 6 presents an alternate embodiment for the drive chain
shown in FIGS. 1 and 2.
[0016] FIG. 7 presents a view taken along line 7-7 in FIG. 6.
[0017] FIG. 8 presents a schematic view of an alternate embodiment
for the conical surface of the variable diameter flanges
illustrated in FIG. 2, illustrating a dual conical angle
profile.
[0018] FIG. 9 presents a crossectional schematic view of an
alternate embodiment wherein the conical face of the variable
diameter pulley flange has convexly configured sprocket bars.
[0019] FIG. 10 presents an alternate embodiment, of my invention,
wherein the inextensible beaded drive chain includes floating
beads.
[0020] FIG. 11 presents a crossectional view taken along line 11-11
in FIG. 6.
[0021] FIG. 12 presents a crossectional view, similar to the top
portion of FIG. 2, showing an alternate embodiment of the variable
pulley.
[0022] FIG. 13 is an elevational view, taken along line 13-13 in
FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring now to FIGS. 1 through 4, FIG. 1 presents a
diagrammatic view of the basic elements of my invention. A pair of
variable diameter pulley assemblies 12 and 14 are positioned on
fixed parallel axes 16 and 18
[0024] Variable diameter pulleys, their structure and operation are
well known in the art as illustrated in the above prior art
references. Therefore only their structure and operation that is
pertinent to the present invention will be discussed in great
detail.
[0025] Referring to FIG. 2, variable diameter pulleys 12 and 14
generally comprise a fixed conical flange 62 and an axially movable
flange, or sheave, 64. However, it is also conceivable that both
flange 62 and flange 64 may be movable. Thus recognizing that both
pulley flanges may be movable, the following discussion will, for
simplicity, assume that only flange 64 is radially movable.
[0026] As flange 64 moves toward and away from fixed flange 62, the
"V" groove between the two flanges will narrow and/or widen
respectively. Thus, for a drive chain having a given chain width,
the effective working diameter of the pulley may be selectively
varied. As the flanges move together, the working diameter of the
flange increases and moves the drive chain radially outward within
the "V" groove. As the pulleys move apart, the working diameter
decreases and the drive chain moves closer to the bottom of the
pulley "V" groove. Thus the "gear" ratio of the input revolutions
per minute (RPM) of input pulley 12 to the output pulley 14 may be
selectively varied by varying the width of the "V" groove of pulley
12, 14 or both to obtain a desired reduction gear ratio between
input pulley 12 and output pulley 14.
[0027] With the above basic understanding of variable diameter
pulleys in a "gear reduction" application, the improvement offered
by the present invention will be discussed in detail below.
[0028] Since the structure of the variable diameter pulley
assemblies 12 and 14 are, for this teaching of the invention,
considered identical, a detailed description of pulley assembly 12
will generally follow with the understanding that both pulley
assemblies 12 and 14 are, basically, identical in structure and
function, and generally interchangeable.
[0029] Generally, power input to the system will be through a
primary or driving variable pulley 12 and transmitted to the
secondary driven variable diameter pulley 14 by way of an endless,
inextensible, chain, notched belt, or beaded chain, as illustrated
by element 22, encircling both the driving pulley 12 and the driven
pulley 14 as illustrated in FIGS. 1 and 2.
[0030] As illustrated in FIGS. 3 and 4, The conical surfaces of
variable diameter pulleys 12 and 14 include radially directed
groove like channels 25 receiving therein elongated sprocket bars
or cogs 26. Channels 25 are circumferentially wider than sprocket
bars 26 thereby permitting circumferential movement of sprocket bar
26 within channel 25 as will be discussed further below. Further,
sprocket bars 26 are resiliently received within channels 25 by
action of one or more compression springs 28, or any other suitable
elastic element, positioned between sprocket bar 26 and the bottom
of channel 25, thereby biasing each sprocket bar 26 outward toward
the surface 66 of flange 64, as illustrated in FIGS. 4 through
4B.
[0031] Alternatively, channels 25 may be shaped as an inverted "T"
and sprocket bars 26 provided with a conforming "T" shape whereby
the channel configuration 25a would retain sprocket bar 26A therein
as shown in FIG. 4A. Similarly, any other type of known
configurations might be used for retaining sprocket bars 26 within
channels 25 such as a wedge or triangular shaped configuration as
illustrated in FIG. 4B. Alternatively, the sprocket bars 26 of FIG.
4 may be retained within their respective channels as taught in my
parent application as identified above.
[0032] Sprocket bars 26 may be configured, as illustrated in FIG.
4, with a wedge shaped top having straight, or flat surfaces 27 or,
as illustrated in FIG. 4A, having scalloped surfaces 29. The exact
configuration of the sprocket bars will necessarily vary depending
upon the application for which they are being used. Shoulder 23 of
sprocket bar 26 preferably extends a distance x above the surface
66 of the pulley flange surface as illustrated in FIG. 4.
[0033] In operation, beads 35 may rest upon shoulder 23 when
engaging the sprocket bars 26 or may ride upon the sprocket bar as
illustrated in FIG. 5. The floatability of sprocket bars 26
compensates for the variation of required length of the
inextensible drive chain, as the working diameter of the variable
pulleys are varied, by floating the drive chain above surface 66 of
the pulley flange as illustrated in FIG. 5. The reader is directed
to my parent application, referenced above, for a detailed
discussion of the required belt or chain length necessary to
encircle pulleys 12 and 14, as the pulley's working diameters
change.
[0034] Referring now to FIGS. 1, 2, and 5. It is assumed for the
following operational discussion that variable diameter pulley 12
is the driving (or input pulley) and variable diameter pulley 14 is
the driven (or output pulley). Driving torque is transferred from
the transmission input means (not shown) to input shaft 68
extending from variable diameter input pulley 12. By an
inextensible chain drive, the driving torque is transferred to
variable diameter output pulley 14 through inextensible beaded
drive chain 22. The output torque is then transferred to the
transmission output shaft 72 extending from variable output pulley
14. When inextensible drive chain 22 is at the exact mid point of
variable diameter pulleys 12 and 14, the gear ratio between pulleys
12 and 14 will be 1 to 1, provided that the pulleys are
identical.
[0035] However, as pulley 12 widens and pulley 14 narrows, as
illustrated in FIG. 2, the ratio of RPM between pulley 12 to pulley
14 will be greater than 1, with the exact ratio being dependent
upon the given working diameters d1 and d2 of pulleys 12 and 14.
Thus input pulley 12 will be turning at a faster RPM than output
pulley 14.
[0036] Except for the floating sprocket bars, many prior patents
teach the above basic principle. For example see U.S. Pat. Nos.
4,433,594; 5,011,461; 6,095,942; 6,135,916; and 6,254,503.
[0037] Referring to FIG. 5, when using an inextensible beaded chain
22 as illustrated, wherein a given gap 30 separates beads 35, one
may not be certain that as chain 22 wraps around the flanges of
variable diameter pulleys 12 or 14 that the sprocket bars 26 will
always be positioned between two adjacent beads. However, by
permitting the sprocket bar 26 to move inward and/or shift
cirumferentially, if a bead 35 impinges upon a sprocket bar as
chain 22 wraps about the pulley's flanges, sprocket bar 26 may move
to accommodate the fixed immovable position of the bead, as
illustrated in FIG. 5, and thereby transmit torque to chain 22.
Although the inextensible chain embodiment illustrated herein
comprises an inextensible beaded chain, other inextensible chain,
and/or belt, configurations are feasible. For example, FIG. 6
illustrates an alternate embodiment for an inextensible, linked,
drive chain 50 wherein a portion of linked chain 50 is illustrated
having hinged, or pivoting links 52. Each link 52 includes a
spherical portion 54 for engagement with sprocket bars 26 on the
flanges of the variable diameter pulleys 12 and 14.
[0038] Further, under certain given circumstances it may be
desirable that variable diameter pulleys 12 and 14 are configured
with a double cone angle as illustrated in FIG. 8. Referring to
FIG. 8, variable diameter pulley flange surface 40 includes a first
conical angle A from the smaller diameter 46 to mid point 44 and a
smaller conical angle B from mid point. 44 to the large diameter
42. Further, it is conceivable that a multiple number (three or
more) of cone angles may be employed with decreasing cone angles as
one moves away from the small diameter end 46 toward the large
diameter end 42.
[0039] In a further alternate embodiment, the multiple angled
conical configuration maybe replaced by a continuously curved
surface such as an elliptical, parabolic, or hyperbolic curved
surface.
[0040] Although eight equally spaced sprocket bars are illustrated,
in FIG. 3, for teaching my invention herein, any number of sprocket
bars may be used. Further it may be advantageous, in some
applications, to space sprocket bars 26 unevenly about the
circumference of the pulley flanges. Also, for particular end uses,
it may be desirable to have different sprocket bar arrangements for
each conical surface of the pulley flange.
[0041] FIG. 9 presents an additional alternate embodiment wherein a
free floating, convexly configured sprocket bar 26a is illustrated.
It is believed that use of a, free floating sprocket bar having a
convex configuration, as illustrated in FIG. 9, may duplicate the
effect of the multi tapered conical flange surface taught above.
The high point 39 of the convexity would be located at the midpoint
of the pulley's conical flange surface 66. In this embodiment it is
conceived that sprocket bar 26a may rock about high point 39, on
the bottom surface of the sprocket channel, and have compression
springs 37a and 37b positioned at each end of sprocket bar 26a
biasing the ends of sprocket bar 26a axially outward.
[0042] A further alternate embodiment of the present invention is
illustrated in FIGS. 12 and 13. In FIG. 12 fixed pulley sheave 62a
includes a vertically configured flange face 67. Flange face 67 may
be smooth and planer, or may include a multiplicity of floating
sprocket bars as taught in FIGS. 2 through 4.
[0043] Although the embodiments as taught herein are believed to be
the most preferred embodiments of the invention, FIG. 10
schematically illustrates an alternate embodiment wherein the drive
chain 22a includes movable beads 35a slidingly received on a
continuous, inextensible, runner, band or cable, 30a. Positioned
upon runner 30a are equally spaced hard stops 33 rigidly affixed to
runner 30a. A locating spring, or any other suitable resilient
means, 31 positions beads 35a midway between the hard stops. Thus
both the sprocket bar 26 and movable beads 35a may cooperatingly
shift circumferentally to accommodate the fixed, inextensible
length of drive chain 22a.
[0044] A further alternate embodiment may comprise a drive chain
such as 22a, as taught immediately above, wherein sprocket bar 26,
having only one degree of freedom, is free to move axially, but not
circumferentially whereby the free float of beads 35a accommodate
the fixed inextensible drive chain length.
[0045] Similar to the free floating beads 35a, as taught
immediately above, the spherical portion 54 of chain link 50, in
FIGS. 6 and 7, may be modified to be free floating within link
50.
[0046] While I have described above the principles of my invention
in connection with specific embodiments, it is to be clearly
understood that this description is made only by way of example and
not as a limitation of the scope of my invention as set forth in
the accompanying claims.
* * * * *